The Arch Installation Framework is the backbone to the Arch Linux distribution installer. The AIF executes all of the routines used to install Arch. More information about AIF proper can be found in the official installation guide.

The AIF configuration file contains variables that define how Arch will be installed. This article describes these variables, and how to make use of the configuration file.

The AIF configuration file

The aif command can be executed with a configuration file which defines how Arch is to be installed. This is a similar concept to Red Hat's kickstart and Debian's preseed. But the similarities end with the concept, thanks to the Arch KISS philosophy the pain involved in automated installs is swept away. AIF is written entirely in bash, and the AIF configuration file is just that, bash. All of the variables and function definitions in the AIF configuration file are sourced shortly after the install begins and applied to the install.

With this in mind, the AIF configuration file is simply a representation of all of that data which can be defined in the global scope of the AIF. This means that available variables can be found in the AIF source code.

Optional variables

The following variables are available in the AIF configuration file:

SOURCE

The source variable will be either CD or net, and will define whether the packages used are locally available or found over the network/Internet.

for local files:

SOURCE=cd

or for a source over the network/Internet

SOURCE=net

FILE_URL

The local directory containing Arch Linux packages, used if SOURCE=cd

FILE_URL=file:///src/repo/pkg

SYNC_URL

The network location used to sync packages over the network. What is important about this variable is that it is the same line that is placed in /etc/pacman.d/mirrorlist. So it is wise to use the $repo and $arch variables:

TARGET_REPOSITORIES

TARGET_PACKAGES_EXCLUDE

TARGET_PACKAGES

Mandatory variables

These variables are the hard ones, and honestly the primary reason for this wiki entry, because they, like the hard drives they configure, can be complicated

GRUB_DEVICE

The GRUB_DEVICE variable is a simple one, it is the device that will hold the grub mbr. This is almost always the primary hard drive.

GRUB_DEVICE='/dev/sda'

PARTITIONS

The partitions line is used to load up sfdisk for disk carving. It is a space delimited list which begins with the device to carve up and then a set of colon delimited arguments which define the device sizes, type and options.

PARTITIONS='/dev/sda 100:ext2:+ 512:swap *:ext4'

Here the disk to be carved up is /dev/sda, 3 partitions will be created, /dev/sda1 will be 100 Megabytes, Linux type, and the "+" sets the grub bootable flag. /dev/sda2 is 512 Megabytes and the swap type, /dev/sda3 will take up the rest of the space, and have the type Linux.

If you want to skip partitioning, override one of the worker functions to do nothing:

worker_prepare_disks () {
true
}

BLOCKDATA

The BLOCKDATA variable is used to determine which partitions are formatted and how they are to be mounted. While static partitions are simple and straightforward, LVM and crypt setups on the other hand can get somewhat messy.

Since AIF translates components of the variables into arguments for commands, understanding what the commands are and how the arguments are passed will greatly assist in understanding how to use the variables.

In this scenario, /dev/vda1 is a raw block device with no label, it is to be formatted with the ext2 file system, yes verifies that it will be formatted, /boot is the mount point, target <Not sure what target means yet>, no_opts is where file system mount options are placed, no_label can be replaced with a file system label. The parameters section is used by more advanced partitioning mechanisms.

Advanced file systems

This example will create a /boot partition and a LVM volume group called *system* with 5 partitions: